Integration of remote microcell with CDMA infrastructure

ABSTRACT

A method of interconnecting a CDMA cellsite having signal advancing capabilities with at least one remote microcell without re-synchronization capabilities. The method of the present invention sufficiently advances the signal to compensate for the time delay induced by communication signal travel over a fiber optic connection between a base station cellsite and a remote microcell.

TECHNICAL FIELD

[0001] This invention relates to a Code Division Multiple Access (CDMA)communication system and more particularly to a CDMA system integratedwith a remote microcell communication system.

BACKGROUND ART

[0002] Microcells in a cellular communication system allow coverage andadditional capacity in an area that is not reachable by a base stationcellsite, such as a CDMA cellsite. The CDMA system has up to six faces.Three are physical faces, which are the three physical faces of thesystem's antenna. There are also three virtual faces that behave as aphysical face but are not a physical part of the antenna of the CDMAsystem.

[0003] Each virtual face can be a remote microcell, and more than oneremote microcell can be integrated with each face. A remote microcell isinstalled in the area of desired coverage and is then connected back tothe base station cellsite through appropriate channels, such as opticalfiber.

[0004] Remote microcell arrangements, however, experience time delays inthe signal caused by the excessive amount of time required for the CDMAsignal to travel from the base station cellsite to the remote microcell,and then to travel through the internal circuitry of the microcellitself. CDMA is a synchronized system, working in conjunction with theGlobal Positioning Satellite (GPS) system, and some microcell systems donot have re-synchronizing capabilities. Therefore, the time delayedsignal emitted by the microcell can also be out of synch with the restof the CDMA system causing communication problems.

[0005] The delayed signal is often compensated for by setting anextremely large search window size parameter to allow a mobile device,i.e. a handset, to access the system. The mobile device will accept alate signal and has the capability to synthesize the late signal.However, this takes up processing power. In addition, a wider searchwindow size takes more time to scan and therefore, adds more time delayin the system making it less reliable. It is desirable to have a narrowsearch window for faster, reliable service.

[0006] The excessive delay caused during a round-trip of the signal canalso result in call setup failures. In general, a predetermined sectorsize that is broadcast to the mobile device establishes the area to beserved. Radio waves take a set amount of time to travel through the airand return. A limit is set for the amount of time given for a signal totravel to the mobile device and broadcast back out, which effectivelycircumscribes an active communication circle around the mobile device.Because of signal delay in the optic fiber, the CDMA system can perceivethe signal delay as an indication that the mobile device is much fartheraway from the microcell than it actually is and the call will not beallowed on the system, thus resulting in call setup failures. It isdesirable to have a large sector size, but the time delay associatedwith a large sector size is undesirable.

[0007] Prior art devices have compensated for the delay between CDMA anda remote microcell by inducing delay in order to provide the appearanceof a synchronized system. In the prior art, the delay is induced toallow greater than one microsecond of difference between the two signalsso that a receiver can provide multipath signals. The system appears tobe synchronized by providing multiple paths for signals to travel.However, this approach does not address the problem of extremely largesearch window sizes and call setup failures.

[0008] It is an object of the method of the present invention tointegrate a microcell system that does not have a re-synchronizingdevice, with a CDMA system to eliminate the above mentioned problemscaused by signal delay associated with remote microcells and CDMA basestations.

[0009] It is another object of the present invention to provide a methodfor integrating the microcell system with the CDMA system by advancingthe signal in order to compensate for time delay generated as a resultof the signal leaving the CDMA cellsite, traveling to the remotemicrocell and returning to the CDMA cellsite.

[0010] It is a further object of the present invention to calculatesuitable values for padding the sector size to eliminate call setupfailures due to the signal delay between the remote and the cellsite.

SUMMARY OF THE INVENTION

[0011] The present invention is a method of integrating a microcellsystem with a CDMA system. The microcell system does not havere-synchronizing capabilities, such as an ADC Kentrox™ system, while theCDMA system has signal advancing capabilities, such as a Lucent™ system.

[0012] The present invention provides a method that determines theamount to advance the CDMA signal so that when it reaches the remotemicrocell, the time delay has been compensated for and the signal issynchronized with the CDMA system. The method also provides fornullifying the round trip time delay allowing call setups to occurnormally.

[0013] The objects and features will become more apparent to one skilledin the art from the following detailed description taken together withthe accompanying drawings and the claims appended hereto.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a block diagram of a CDMA base station cellsite and itsinterrelationship with a plurality of remote microcells;

[0016]FIG. 2 is a flow chart depicting the measurement section;

[0017]FIG. 3 is a sample format for recording data measurements andcalculations for a stand alone CDMA;

[0018]FIG. 4 is a sample format for recording data measurements andcalculations for a simulcast CDMA;

[0019]FIG. 5 is a flow chart depicting the installation section for thestand alone CDMA;

[0020]FIG. 6 is an interconnection diagram for the stand alone CDMA;

[0021]FIG. 7 is a flow chart depicting the installation section for thesimulcast CDMA;

[0022]FIG. 8 is an interconnection diagram for a simulcast CDMA;

[0023]FIG. 9 is a flow chart depicting the calculations section;

[0024]FIG. 10 is a flow chart depicting the translation section;

[0025]FIG. 11 is a flow chart depicting the level setting section; and

[0026]FIG. 12 is a flow chart depicting the testing section.

BEST MODE(S) FOR CARRYING OUT THE INVENTION

[0027] The present invention will be described in conjunction with anADC Kentrox™ microcell and a Lucent™ CDMA base station. However, itshould be noted that the method's success does not rely on thesemanufacturers alone, and it is possible to apply the method to otherremote microcell systems that do not have re-synchronizing capabilitiesalong with other CDMA base stations that have signal advancingcapabilities.

[0028] Referring to FIG. 1 there is shown a block diagram of a CDMA basestation 10 or cellsite having six faces 11. Three of the faces arephysical; namely A, B and C and three faces are virtual, namely D, E,and F. The base station 10 is in communication with a plurality ofremote microcells 12 that are linked by optical fibers 14. The length ofthe fibers 14 varies and can be up to several miles long. So while theremote microcells 12 provide cellular coverage in an area that would nototherwise be accessible, the fiber optic connections induce a time delayin the communication signal which degrades the communicationcapabilities of the overall system.

[0029] The method of the present invention provides enhancedcommunication between remote microcells and CDMA systems in bothsimulcast and stand alone configurations. A simulcast CDMA system sharesa group of circuits between the base station cellsite 10 and themicrocells 12. The simulcast CDMA provides radio coverage to an areathat would not otherwise be covered by the existing base stationcellsite 10. The addition of the remote microcells 12 does not affectthe total number of circuits. Therefore, signal blocking can occur ifthe demand for circuits exceeds the supply.

[0030] In a stand alone configuration, a group of circuits is dedicatedto the remote microcell 12, and are not shared with the base stationcellsite 10. Therefore, radio coverage is provided to an area that wouldnot otherwise be covered by the existing base station and the totalcapacity of the cellsite is increased because the number of circuits isincreased. It is less likely that blocking will occur because of theincreased number of circuits. However, the stand alone system requiresmore hardware and is therefore more expensive than the simulcast CDMA.

[0031] In general the overall method is the same for both the simulcastand stand alone CDMA systems, with only minor differences that will bepointed out during the detailed description as necessary.

[0032] For both systems there are several initial conditions that mustbe satisfied before proceeding with the method of the present invention.The microcell must be physically connected to the base station cellsite.The radio spectrum must be cleared using any known method to ensure thesuccessful transmission of the CDMA signal. For the stand aloneconfiguration, a fully equipped stand alone CDMA shelf must be installedfor each remote microcell to be integrated.

[0033] The method of integration for both the simulcast and stand aloneCDMA configurations can be divided into six sections categorized asfollows: Measurements, Installation, Calculations, Translations, LevelSetting and Testing. It is possible to integrate more than one remotemicrocell to each CDMA cellsite, and the sections of the method must beexecuted separately for each remote being integrated.

[0034] The method generally includes taking necessary measurements toperform calculations for setting translation values and power levels inthe system so that the signal is advanced to avoid time delaycommunication problems and the sector size is calculated and adjusted toavoid call setup failures.

[0035] Measurements Section

[0036] The method of the present invention begins by measuring thelength of the fiber optic connection between the CDMA base stationcellsite 10 and the remote microcells 12, the loss in the fiber opticconnections, and the power output at the remote microcells 12. See FIG.2, which depicts the measurements section 20 of the method in flow chartform. The measurements section 20 obtains the necessary measurement thatare required to calculate the proper translation values and power levelsettings necessary in later sections of the method.

[0037] The first step in taking the necessary measurements requireschecking 22 the CDMA base station cellsite to ensure it is in normaloperating condition. Using interfacing software, one skilled in the artis capable of determining the status of the CDMA cellsite and making thenecessary changes should the cellsite be out of its normal condition.Any maintenance deficiencies and repairs 23 should be made beforeproceeding with the measurements section 20.

[0038] The remote microcell, or face, to be integrated should be removedfrom the cellsite in order to service it under the method of the presentinvention. None of the measurements should be taken until all activecalls have been dropped from the remote microcell.

[0039] The fiber length must be measured first for a lower wavelength24. This can be done by a variety of methods known to one of ordinaryskill in the art. The following description is merely an example. Theoptic fiber 14 should be disconnected at the remote 12 end. The opticfiber 14 is removed at the base station cellsite and connected to anOptical Time Domain Reflector (OTDR).

[0040] A lower wavelength is selected. For example, 1310 nm is the lowerwavelength specific to the microcell manufacturer for this example. Amaximum value is also selected, which value should be in kilofeet (kft)for convenience in the calculations section. The value chosen for themaximum range should be estimated to be equal to or greater than theactual length of the fiber 14 between the cellsite 10 and the remote 12.Typically this range is approximately 13 kft.

[0041] Using a 2-Point method, the OTDR will measure the loss anddistance in the fiber 14. The distance (in kft) and loss (in dB) arerecorded 26 on a data sheet: FIG. 3 depicts a sample data sheet relativeto the stand alone CDMA and FIG. 4 depicts a sample data sheet relativeto the simulcast CDMA. The distance and loss for the lower wavelengthmeasurement will be displayed between the falling edge of the firstsignal pulse and the rising edge of the last pulse. If the distancebetween the two pulses is less than half of the width displayed, then asmaller distance value is chosen for the range and the 2-Pointmeasurement is repeated. If no more than two pulses are displayed, alarger distance value should be chosen for the range and the 2-pointmeasurement should be repeated.

[0042] It is also necessary to measure the fiber length for an upperwavelength 28. S sample upper wavelength is selected, for example 1550nm due to the manufacturer of the microcell in the present example, andthe 2-Point measurement steps are repeated. The results are alsorecorded 30 on a data sheet. After the fiber length in the upperwavelength is measured, the fiber is reconnected at the remote location.If more than one remote 12 is being integrated, the above steps shouldbe repeated for each remote. Once all remote measurements have beentaken, the fibers can be reconnected at the base station cellsite.

[0043] The next step is to measure the power output at the remotemicrocell 32. A power meter and sensor should be zeroed and calibratedto ensure accurate measurements. the antenna feedline from the remotemicrocell's RF output connector is disconnected, and the power sensor tothe RF output is connected. A single Voice-Radio Channel Unit (V-RCU) isthen identified as the “master” radio for the remote to be integrated.The radio number and channel should be noted for future reference. Oncethe radio is configured as the “master”, the radio transmitter is turnedon. The radio is set to the same Voice Radio Attenuation Level (VRAL)setting as the remote 12 uses in normal operation. The output power ismeasured in dBm and the values are recorded 34 on the data sheet.

[0044] Subsequently, the radio is deconfigured and the antenna feedlineis reconnected to the remote's RF output power connector. The powermeasurements are repeated with the power sensor connected to theremote's RF monitor port 36 and the results are recorded 38. The powermeasurements are repeated and determined for all of the remotes beingintegrated.

[0045] The power meter is then applied to the base station cellsite tomeasure the output power of one radio at the input of one cellsitedigitizer 40. The cable between the output of the Radio Interface Module(RIM) card 39, (see FIG. 6), and the input of the first digitizer isdisconnected. The power output of the digitizer is measured by followingthe same steps outlined above for measuring the power output at the RFoutput connector. This is accomplished for each digitizer of the CDMAcellsite and the results are recorded 42.

[0046] For a simulcast CDMA only, the power output for the CDMA shouldbe measured at the output port of the transmitter base station 44, alsoknown as the foam jumper, for each remote being integrated. It isimportant to make sure that all of the digitizers that were removed foroutput power measurements in the previous step are reconnected beforemeasuring the output power at the foam jumper 44. The results are againrecorded 45.

[0047] For both the simulcast and stand alone CDMA's, the followingadditional data should be collected 46:

[0048] (a) the total number of radios assigned to the remote beingintegrated with the CDMA;

[0049] (b) the number of radios assigned to the remote which are in theCDMA bandwidth that have been removed from service when spectrumclearing is initiated;

[0050] (c) the RIM card transmit and receive antenna attenuation settingfor each remote being integrated;

[0051] (d) the version of the digitizer used for each remote;

[0052] (e) the remote attenuation level;

[0053] (f) the Baseband Combiner and Radio (BCR) attenuation of theremote being integrated; and

[0054] (g) the pn-offset of the remote being integrated.

[0055] These values should be recorded 48 on the respective data sheetfor future reference in the calculations and translations sections forthe method of the present invention.

[0056] Installation Section

[0057] The purpose of the installation section is to accomplish thephysical interconnection of the microcell hardware to the CMDA basestation cellsite. Additional measurements are taken as necessary. Theinstallation is different for the stand alone and simulcast CDMAsystems.

[0058] Stand Alone CDMA Installation

[0059] Referring to the flow chart of FIG. 5, the method of installation50 for a stand alone CDMA is shown. For the stand alone CDMA system, a4:1 combiner is installed 52 for each face, and the input cable from theassociated Base Band Assembly (BBA) is connected to the proper input ofthe 4:1 combiner (see FIG. 6 for the hardware interconnection diagramfor the 4:1 combinwer 53). The output power level reading is measured 54at the 4:1 combiner. The BBA is restored to service and the output gainpotentiometer of the BCR is adjusted to an output level of −23 dBm. TheBBA is then removed from service to avoid transmitting from the BBA withno load. As shown in FIG. 6, one end of the transmit cable 55 isconnected to the 4:1 combiner 53 for the remote being integrated, andthe other end of the transmit cable 55 is connected to the nextavailable input on the RIM card 39.

[0060] A 10 dB attenuator 57 is connected 56 to the top of the 4:1combiner 53 in the CDMA for the remote being integrated. One end of thereceive cable 58 is connected to the attenuator 57 and the other end ofthe receive cable 58 is connected to the next available input on the RIMcard 39. Finally, the 4:1 combiner 53 is terminated with a 50Ωterminator 59. The next step is to proceed to the calculations section.

[0061] Simulcast CDMA Installation

[0062] For the simulcast CDMA, the installation section 60 is depictedas a flow chart in FIG. 7. The hardware interconnection diagram isdepicted in FIG. 8. The first step is to insert 62 a 2:1 combiner 67 onthe transmit cable 63. The transmit cable 63 that runs to the LinearAmplifier Circuit (LAC) of the CDMA from the 4:1 combiner 65 is removedand connected to a 2:1 combiner 67. The transmit cable for the microcellis then connected to the 2:1 combiner 67, and the transmit cable isconnected to the next available input on the RIM card 39.

[0063] The next step is to insert 64 a 2:1 combiner 67 on the receivecable 69. The existing receive cable is removed from the top of the 4:1combiner 65, and connected to the 2:1 combiner 67. A 6 dB attenuator 71is connected 66 to another port of the 2:1 combiner 67 and the receivecable 69 is then connected to the 6 dB attenuator 71. The Receive cable69 is connected to the next available input on the RIM card 39. Aconnection should also be made between the center of the 2:1 combiner 67and the antenna interface frame (not shown). The receive cable 69 isalso re-connected to the top of the 4:1 combiner 65.

[0064] The BBA is restored to service 68, and the output gainpotentiometer is adjusted on the BCR until the output level 44previously recorded in the measurements section 40 is displayed.Finally, the BBA is removed from service unconditionally 70. The nextstep is to proceed to the calculations section.

[0065] Calculations Section

[0066] A flow chart for the calculations section 80 is shown in FIG. 9.The calculations section 80 uses the data obtained in the measurementssection 20 to define values that will be used in the translations 100and level setting sections 200 of the method that will allow the signalto be sufficiently advanced to as to compensate for the time delay. Thecalculations are very similar for both the stand alone CDMA and thesimulcast CDMA and the differences will be pointed out accordingly.

[0067] The first calculation is the transmit antenna propagation delaycalculation 82. The maximum forward path propagation delay is determinedand this value is recorded in the data sheets for each remote on theface being integrated. For this purpose, the following calculation tablecan be used: Fiber distance measurement in kft for remote: Conversionfactor for kft to miles: ÷  5.280 Conversion factor for fiber distanceto delay: ×  7.878 Add propagation delay induced by cellsite: + 22.80Add propagation delay induced by digitizer: + 1 or 8 Total transmitpropagation delay for this remote: =

[0068] This calculation is repeated for each remote on the face beingintegrated and the results are recorded on the respective data sheet.

[0069] After the forward path propagation delays have been calculatedfor all the remotes on the stand alone CDMA face, the lowest value 84 onthe data sheet is selected. This value is used in the translationssection 100.

[0070] Unlike a stand alone CDMA, the changes made to the operatingsystem for a simulcast microcell also affect the base station cellsite.To avoid altering the operation of the base station, a default value of22.8 microseconds 86 is used in the translations section 100 for thesimulcast CDMA method. This value is recorded in the simulcast datasheet (FIG. 4). While this value is 22.8 microseconds for the presentexample, it will vary depending on the manufacturer and may vary withdifferent equipment.

[0071] Next, for both stand alone and simulcast CDMA, the maximumreceive path propagation delay 88 is determined for each remote on theface being integrated and these values are recorded 90 on the respectivedata sheet. The following calculation table may be used: Fiber lengthfrom measurements section: Conversion factor for kft to miles: ÷  5.280Conversion factor for fiber distance to delay: ×  7.878 Add propagationdelay induced by cellsite: + 14.00 Add propagation delay induced bydigitizer: + 3 or 17 Total receive path propagation delay for thisremote: =

[0072] After the receive path propagation delays have been calculatedfor all remotes on the stand alone face, the lowest value in the standalone data sheet is selected and recorded 90. This value is used in thetranslations section 100.

[0073] Since changes made for a simulcast microcell also affect the basestation cellsite, a default value 92 of 14.0 microseconds is used in thetranslations section. This value is recorded in the simulcast datasheet. Again, this value is dependent upon the specific equipment usedand may vary with a different manufacturer.

[0074] The next step is to determine the maximum transmit differentialdelay 94 of all remotes on the face being integrated by calculating thedifferential delay for each remote. The results should be recorded inthe data sheet. There are different procedures for the stand alone andsimulcast CDMA systems. The following calculations table highlight thedifferences.

[0075] For the stand alone CDMA, the calculation table is as follows:Transmit antenna propagation delay: Receive antenna propagation delay: +Enter subtotal from above: = Average subtotal: ÷ 2 Total transmitdifferential delay for this remote:

[0076] This calculation is repeated for each remote on the face beingintegrated, and recorded 96 on the stand alone data sheet.

[0077] For the simulcast CDMA, the calculation table is slightlydifferent: Transmit antenna propagation delay: Receive antennapropagation delay: + Base station induced transmit propagation delay: −22.8 Base station induced receive propagation delay: − 14.0 Entersubtotal: = Average subtotal: ÷  2 Total transmit differential delay forthis remote: =

[0078] The difference for the simulcast CDMA is that the default valuesof the actual delay of the base station transmitter and the base stationreceiver are included to ensure the base station remains unaffected. Forthe present example, the base station transmitter delay is 22.8microseconds and the base station receiver delay is 14.0 microcseconds.These values are specific to the equipment manufacturer and may varywith other manufacturer's equipment.

[0079] This calculation is repeated for each remote on the face beingintegrated and the results are recorded 96 in the simulcast data sheet.If this value exceeds a predetermined time limit, 90 microseconds in thepresent example, the face cannot be successfully integrated. Thehardware has sepcific limits built into it that cannot be over-ridden.Therefore, if the time delay is more than the built-in limits of thehardware, it will not be possible to advance the signal.

[0080] Selecting the maximum value to be used in the translation sectionis the same for both the stand alone CDMA and the simulcast CDMA. Eachremote's data sheet should be examined to find the largest and smallestvalues of the transmit differential delay calculated in the previousstep. The maximum differential delay 95 is calculated using thefollowing data table and the value is recorded 96 on the data sheet:Largest transmit differential delay of all remotes: Smallest transmitdifferential delay of all remotes: − Maximum transmit differentialdelay: =

[0081] The next step is to calculate the sector size 98 for the facebeing integrated. The method of the present invention pads the sectorsize value so that suitable values for the sector size allow call setupswithout failure.

[0082] The following calculation table can be used to determine thesector size translation value: Maximum transmit differential delay: Addfree-space propagation delay for 3 miles: + 16.08 Enter subtotal: =Convert microseconds to miles: ÷  5.36 Sector size:

[0083] This value should be recorded on the respective data sheet 100.The free-space propagation delay for 3 miles is factored into thecalculation to ensure sufficient overlap of the sector size. This valuewill be manufacturer dependent and could vary depending on the equipmentdesign.

[0084] The next calculation is the search window size 102 for the facebeing integrated. This varies slightly between the stand alone CDMAconfiguration and the simulcast CDMA configuration. This value should berecorded 104 on the data sheet.

[0085] The following calculation table is for a stand alone CDMA:Maximum transmit differential delay: Additional delay based onassumption + 16.28 remote is within 3 miles of nearest neighbor:Subtotal: Double for + and − center of window: ×  2 Cell search windowsize:

[0086] The following calculation table' is used for a simulcast CDMA:Maximum transmit differential delay: Base station induced propagationdelay: − 14.0 Additional delay based on assumption + 16.28 remote iswithin 3 miles of nearest neighbor: Subtotal: Double for + and − centerof window: ×  2 Cell search window size:

[0087] The simulcast CDMA must include the manufacturer's default valuefor the delay induced by the base station transmitter. This is theactual delay induced by the base station transmitter.

[0088] The next steps involve power calculations that are the same forboth the stand alone CDMA and the simulcast CDMA. The actual inputanalog power to the digitizer is determined when all radios on the faceto be integrated are active 106. The following calculation table may beused: Total number of radios on face: Number of radios removed fromface: − Subtotal: = Logarithm (base 10) of subtotal: log Multiply by afactor of 10: × Power measured for 1 radio at input to digitizer:Composite analog power to input of digitizer:

[0089] The sign of the analog radio input power may be a negative valueand should be scrutinized.

[0090] The total gain and the actual gain of the system for each remoteon the face being integrated is calculated next by using the followingcalculation table. The calculations are the same for both the standalone CDMA and the simulcast CDMA. For the total gain calculation 108,the following data table is used:

[0091] Output power measured in measurements section:

[0092] Input power for one radio measured at input to digitizer:

[0093] LPA attenuation of remote:

[0094] Total gain of system for this remote:

[0095] This calculation is performed for each remote on the face beingintegrated, and the results are recorded on the data sheet 110.

[0096] The actual gain of the system 112 is calculated for each remoteon the face being integrated using the following calculation table:Output power measured at remote: Input power for 1 analog radio measuredat digitizer input: − LPA attenuation of this remote: + Actual systemgain for this remote: =

[0097] This calculation should be made for each remote on the face beingintegrated and recorded on the data sheet 114.

[0098] Next, it will be necessary to calculate the CDMA input powerlevel to the digitizer 116 to determine the adjustment that needs to bemade to the Baseband Combiner and Radio. The following calculationstable may be used for both a stand alone and a simulcast CDMA: +26 dBmfor CDMA: 26 Expected System gain (given by Microcell Mfr.): − 61 LPAAttenuation previously calculated: + Adjust CDMA input level atdigitizer to this amount: =

[0099] This calculation is repeated for each remote on the face beingintegrated, and recorded 118 in the data sheet.

[0100] The total CDMA and analog composite power 120 is determined whenall radios on the face to be integrated are active and all CDMA channelson the face are active. The sign of the analog or CDMA input powershould be noted, as the value may be negative. Analog composite power todigitizer: Divide by 10: +10 Raise analog composite power to the powerof base 10: 10^(×) CDMA ideal composite power level to digitizer: Add7dB to allow for a fully loaded CDMA: +7 Divide by 10: ÷10 Raise resultto the power of base 10: 10^(×) Add Analog composite power total: +Subtotal: = Logarithm (base 10): log Multiply by 10: ×10 Analog anddigital composite power to input of digitizer: =

[0101] Translations Section

[0102] In the translations section 200 of the method of the presentinvention, the appropriate values are entered into the system database210 to allow the microcell to function in the CDMA system (see FIG. 10).Some values are assumptions based on the manufacturer's specificationsthat can be substituted for manufacturer's other than those discussedherein. Other values are taken from the calculations section.

[0103] For a stand alone CDMA, the following translations are made:

[0104] Transmit Antenna Propagation Delay from Calculations Section:

[0105] Receive Antenna Propagation Delay from Calculations Section:

[0106] Search Window Size from Calculations Section:

[0107] Sector Size from Calculations Section: Maximum DifferentialTransmit Delay from Calculations Section: Initial Power Offset forAccess (Mfr. Spec.): −5 Access Probe Power Increment (Mfr. Spec.): 4 BCRAttenuation Factor (Mfr. Spec.): 6 Access Channel Preamble Length (Mfr.Spec.): 2 Time Randomization for Access Channel Probes (Mfr. Spec.): 6Eb/No Setpoint - Minimum (Mfr. Spec.): 5 Eb/No Setpoint - Maximum (Mfr.Spec.): 9.8

[0108] For a simulcast CDMA, the following translations are made:

[0109] Transmit Antenna Propagation Delay from Calculations Section:22.8

[0110] Receive Antenna Propagation Delay from Calculations Section: 14

[0111] Search Window Size from Calculations Section:

[0112] Sector Size from Calculations Section: Maximum DifferentialTransmit Delay from Calculations Section: Initial Power Offset forAccess (Mfr. Spec.): −5 Access Probe Power Increment (Mfr. Spec.): 4Access Channel Preamble Length (Mfr. Spec.): 2 Time Randomization forAccess Channel Probes (Mfr. Spec.): 6 Eb/No Setpoint - Minimum (Mfr.Spec.): 5 Eb/No Setpoint - Maximum (Mfr. Spec.): 9.8

[0113] The database should be updated so that the operating system usesthe above entered values ensuring the signal is sufficiently advanced tocompensate for the time delay generated during the signal's travel overthe fiber optic connection. The translation values also ensure that thesector size is sufficiently padded to avoid call setup failures.

[0114] Level Setting Section

[0115] The level setting section 300 uses previous measurements andcalculations to ensure the analog and CDMA output levels are properlyset. A flow chart is shown in FIG. 11.

[0116] The first step is to configure the CDMA for pilot-only 310 byupdating the database. The pilot acts as a beacon for a mobile device tolocate the base station. Pilot-only ensures the CDMA channels aresufficiently referenced to a known and repeatable state. The existingvalues for the paging channel gain and synchronization channel gain arerecorded, then the values are updated to zero. These changes to thedatabase will take effect by logically removing and then restoring theCDMA cluster controller (CCC) for the face being integrated.

[0117] For the stand alone CDMA, the power sensor is reconnected to thedigitizer input cable previously used for the analog radio powermeasurement, and the BBA is logically restored to serviceunconditionally. The CDMA output power to the input of the digitizer 320is adjusted by observing the display of the power meter and adjustingthe output power potentiometer on the front panel of the BCR until themeter reads the value calculated 106 in the calculations section 80.

[0118] For the simulcast CDMA, the power sensor head is removed from thefoam jumper and the foam jumper is reconnected to the waveguide fromwhich it was removed. The first remote for the face being integrated isselected, and the power sensor head is connected to the input cable ofthis remote's digitizer. The BBA is logically restored to serviceunconditionally, and the power meter display is observed 330. It shouldbe within ±3 dBm with the ideal input level calculated in thecalculations section. If the display exceeds the value by more than 3dBm, the appropriate in-line attenuator should be used on the transmitcable to reduce the signal to within 3 dBm of the ideal level. If thevalue is less than the ideal level by more than 3 dBm, it is possiblethat there may be insufficient signal strength to make CDMA calls fromthe microcell. This can be determined in the testing section.

[0119] For both the stand alone and simulcast CDMA, the BBA is logicallyremoved from service unconditionally and the digitizer is reconnected340.

[0120] For a simulcast CDMA, the power display comparison is repeatedfor each remaining digitizer on the face being integrated.

[0121] For both the stand alone and simulcast CDMA's, the paging channelgain and synchronization channel gain are restored 350 to the valuesrecorded above, before these values were set to zero.

[0122] Testing Section

[0123] A flow diagram for the testing section 400 is shown in FIG. 12.After restoring the cellsite to normal service 410, the testingprocedures ensure the newly integrated face is operating normally. Thetesting procedure checks for RF leakage in the cellsite and for normalpropagation at each remote.

[0124] The previously configured “master” radio is restored to service420. The BBA for the newly integrated face is logically restored toservice unconditionally. The database is updated 430 by logicallyremoving and restoring the CCC for the newly integrated face. The CDMAis powered up and tested with a mobile device 440. The mobile device ismoved about the cellsite until the newly integrated face is shown on thephone's display. The system is then accessed by dialing a workingnumber. After the call has been established, it should be verified thatit is digital service. If the call is consistently forced to analog,ensure the paging channel and synchronization channel have been reset,and the CCC removed and restored. If access is still not possible, thecellsite should be cleared and the test repeated.

[0125] The service in an area close to the remote should be tested toobtain service from the remote 450. The remote should be fullyfunctional on a CDMA call. This step should be repeated for each remoteon the newly integrated face.

[0126] The above described method of six sections interconnects a CDMAcellsite, in either a stand alone or simulcast configuration, with amicrocellular infrastructure which allows CDMA calls to be processedthrough the microcell without undue signal delay, without an oversizedsearch window, and with a padded sector size. The signal is advanced sothat the delay is unnoticed by the CDMA system and all communicationsremain in synchronization, enabling reliable call handling between acellsite and a remote microcell.

[0127] Various modifications of the invention, in addition to thoseshown and described herein, will be apparent to those skilled in the artfrom the foregoing description and accompanying drawings. Suchmodifications are intended to fall within the scope of the appendedclaims.

What is claimed is:
 1. A method for integrating at least one remote of amicrocellular communication system with at least one face of a codedivision multiple access (CDMA) communication system, said CDMA systembeing capable of signal advancing, said method comprising the steps of:measuring fiber length and remote power output; interconnecting hardwarebetween said at least one remote and said at least one face; performingcalculations using data obtained from said step of measuring todetermine how much to advance said CDMA signal; translating saidcalculations to a database for advancing a signal allowing said at leastone remote to communicate with said at least one face; and settingoutput levels of said CDMA system said output levels determined basedupon said measurement data and said calculations.
 2. The method of claim1 further comprising the step of testing said method for properoperation.
 3. The method of claim 2 wherein said step of testing furthercomprises testing said system at said at least one face and at said atleast one remote.
 4. The method of claim 1 wherein said microcellularcommunication system further comprises a stand alone microcellularcommunication system.
 5. The method of claim 4 wherein said step ofinterconnecting hardware further comprises the steps of: installing acombiner for each face to be integrated; connecting a meter to said CDMAsystem for taking output power readings; connecting a transmit cable toeach of said combiners; connecting a receive cable to each of saidcombiners; and terminating said receive cable.
 6. The method of claim 1wherein said microcellular communication system further comprises asimulcast microcellular communication system.
 7. The method of claim 6wherein said step of interconnecting hardware further comprises thesteps of: connecting a transmit cable to said at least one face;connecting a combiner to said transmit cable; connecting said transmitcable to an interface module for said remote; connecting a receive cableto said interface module for said remote; connecting a combiner to saidreceive cable; connecting an attenuator to said combiner; connectingsaid attenuator to said receive cable; and connecting said receive cableto said at least one face.
 8. The method of claim 1 wherein said step ofmeasuring further comprises the steps of: verifying said at least oneremote is in normal condition; isolating said at least one face;measuring said fiber length of said at least one remote; measuring saidpower output of said at least one remote; and recording additional datanecessary for said steps of performing calculations and translating. 9.The method of claim 8 wherein said step of measuring further comprisesthe steps of recording said CDMA output power level.
 10. The method ofclaim 1 wherein said step of performing calculations further comprisesthe steps of: calculating propagation delay for a transmit antenna forsaid at least one remote; calculating propagation delay of a receiveantenna for said at least one remote; selecting and recording a lowestvalue of said propagation delay calculations for both said transmit andsaid receive antennas; calculating a maximum differential delay of alldelay calculations completed for said at least one remote; calculating asector size; determining a cell search window size; calculating actualinput analog composite power; determining total gain for said at leastone remote; determining actual gain for said at least one remote;calculating CDMA input power for said at least one remote; and checkingpower calculations.
 11. The method of claim 10 wherein for a simulcastCDMA said step of selecting and recording a lowest value of saidpropagation delay calculations for both said transmit and said receiveantennas further comprises selecting a fixed value for said propagationdelay for each of said transmit and said receive antennas, said fixedvalue based on an equipment specification.
 12. The method of claim 1wherein said step of translating further comprises the step of updatinga database for said at least one remote and said at least one face to beintegrated by loading said database with values derived in said steps ofcalculating and translating to compensate for time delay by advancingsaid CDMA signal.
 13. The method of claim 1 wherein said step of settingoutput levels further comprises the steps of: ensuring output levels areproperly set by using values derived in said steps of measuring andperforming calculations; and restoring said at least one face to normalservice.